A Question Regarding Excess Charge....

[Lagoon4us]

Originally Posted by Stu Jackson

There was a skipper over on Sailnet about six months ago who was trying to do this. One of his ideas was that since he wasn't at the boat all the time (i.e., going ashore to shop, or going home for a week) that when he'd come back to his boat he'd have hot water. The group disabused him of this notion, suggesting that it would be safer if he did it manually and used his battery monitor to, ehm, actually monitor what was going on.

It takes all of fifteen minutes to heat a six gallon tank with a 120V heater element. While you can do the math, the aforementioned load of around 80A sounds right when heating with the inverter. If the batteries are topped off or over 90% soc and you have a good solar system, and a good sized house bank, this should be no challenge at all.

I simply don't understand the need or desire to do this "automatically." It would seem to be much safer to do it while you are there and monitoring the results. Sometimes I think we all may tend to overcomplicate things when trying the more sophisticated automatic approaches, which end up with more parts and more connections. Every electrical connection is a weak link in the chain.

djmarchand's answer was right on.

Your solar controller should step itself back anyway based on battery acceptance.

Agree with some of your points however when we are not on the boat the systems are always reduced to a minimum.
To fall in line with your suggestion what read-out do you reccomend that accurately tells me that we have reached 90% charge so confidently we can startup the inverter?
We have a MorningStar RM1 and that gives only max and min voltages and voltage status along with battery temps. Cheers Frank